From cave dwellers to condo owners, humans have been on a never-ending quest to develop devices to make their homes more comfortable. However, most of the items we use today--from refrigerators to stereos--were invented only in the past century. What was the world like before the advent of automatic flush, the walkman, and the DustBuster--not to mention the introduction of plastics and indoor plumbing? Read on to find out more about appliances, plastics, stereos, and plumbing, and then ask our experts anything you've ever wanted to know about these household wonders!